1. Field of the Invention
The present invention relates to a display device.
2. Description of the Related Art
In a liquid crystal display device including an edge-lit backlight unit, light entering an edge surface of a light guide plate travels inside the light guide plate, and is reflected at an interface on a rear surface side of the light guide plate to exit from a front surface thereof (see Japanese Patent Application Laid-open No. 2009-276531). Specifically, on the rear surface side, mountain-like convex portions or valley-like concave portions are formed so that ridge lines thereof extend in a direction orthogonal to the traveling direction of light. Light reflected by the convex portions or the concave portions exits from the front surface. Further, there is also light returning inside by being reflected at an interface on the front surface side. In order to cause convergence of this light, on the front surface side, mountain-like convex portions or valley-like concave portions are formed so that ridge lines thereof extend in a direction parallel to the traveling direction of light.
Light traveling inside the light guide plate includes light to be reflected at the interface on the rear surface side, and in addition, light that passes through the rear surface. In order to return the light that has passed through the rear surface to the light guide plate, a reflective sheet is arranged. In recent years, there is a case where a reflective sheet having high reflectance ratio is used. However, because the reflective sheet can be brought into intimate contact with the light guide plate, there arises a problem that light that is supposed to be reflected at the interface on the rear surface of the light guide plate is absorbed in the reflective sheet. As a countermeasure against this problem, it is conceivable to reduce the degree of intimate contact by roughing the rear surface of the light guide plate by blasting. However, in this case, the shapes of the convex portions or the concave portions on the rear surface are changed, and hence the brightness distribution is changed.